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Quiz on Spent Fuel Pool Safety/Security

  1. If you lose the spent fuel pool (SFP) cooling system, how long does it take to heat up and boil off the pool inventory to critical level? Assume your last fuel discharge is fairly recent (a few months ago).
    A. A few hours.
    B. A few days.
    C. A few weeks.
    D. A few months.
  2. In a SFP accident, what does the "critical" level mean? How is it defined?
    A. When the pool water starts boiling.
    B. Water level drops to 3 feet above the fuel and the radiation level in the area becomes inaccessible to people.
    C. Water level is at the top of the fuel.
    D. The pool is boiled dry.
  3. Is a catastrophic earthquake or heavy load drop possible to drain the pool rapidly (than boil-off by loss of cooling)?
    A. Yes.
    B. No.
  4. Is return-to-criticality by a cask drop at a SFP possible?
    A. Yes for both PWR and BWR.
    B. Yes for PWR but not BWR.
    C. Yes for BWR but not PWR.
    D. Not possible for both PWR and BWR.
  5. What is the likely consequence for a return-to-criticality event for a light water reactor's SFP?
    A. Catastrophic explosion, Chernobyl type consequence.
    B. Sudden neutron flux increase, fatal dose to people in the neighborhood.
    C. Localized and limited damage to affected assemblies, self-regulating, criticality will not last long.
  6. After water level drops to the critical level and without cooling, how long does it take for the fuel clad to heat up to release radioactivity? On the order of:
    A. Minutes.
    B. Hours.
    C. Days.
    D. Weeks.
  7. When the fuel cladding zirconium is heating up, what chemical reaction is likely to happen?
    A. Zr - water (steam) reaction to generate hydrogen and turn into zirconium oxide.
    B. Oxidation with air and become zirconium oxide ( zirconium fire).
    C. Both a and b if water (steam) is present.
    D. No reaction.
  8. The oxidation process is
    A. heat absorbing and will not ignite.
    B. exothermic and may become self-sustaining.
  9. True or false: Maintaining ventilation in the building will help zirconium surface cooling and prevent zirconium fire.
    A. True.
    B. False.
  10. True or false: After zirconium fire has taken place (at temperature > 1600°F), maintaining ventilation in the building will fuel the fire.
    A. True.
    B. False.
  11. Compared to a worst case power plant accident, the consequences of a worst case SFP accident are likely to be
    A. more severe.
    B. less severe.
    C. comparable.
  12. The instant death estimate for the worst case SFP release is in the order of
    A. 10's.
    B. 100's.
    C. 1000's.
    D. 10,000's.
  13. The late (cancer) death estimate for the worst case SFP release is in the order of
    A. 10's.
    B. 100's.
    C. 1000's.
    D. 10,000's.
  14. The late (cancer) death is mostly due to the radioactive release of
    A. Noble gases.
    B. Iodine.
    C. Cesium 137.
    D. Ruthenium 106.
  15. Taking potassium iodide (KI) will block further absorption of which radioactive isotopes in the thyroid?
    A. Noble gases.
    B. Iodine.
    C. Cesium 137.
    D. Ruthenium 106.

Your score:

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PCTRAN-SFP Features and Capabilities

PC-Windows based SFP simulator and analytical tool for emergency exercise and training. Can even be used as a demonstration tool for non-technical audience, such as management, policy makers, and the general public.

  • Plant specific in SFP geometry, cooling system, fuel burn-up history and isotope inventory.
  • For any given drain-down, drop-cask or loss-of-cooling event, provides instant estimate of pool boiling and dose release time.
  • Determines the possibility of return-to-criticality.
  • Selectable high-fidelity real-time or fast-time simulation.
  • Calculates zirconium fire and steam interaction rate.
  • Prediction of clad burst, fission product release timing and pattern.
  • Complies with NUREG 1738 (SFP accident), 1465 (Revised Source Term), etc.
  • Projects release isotope strength and site boundary doses.
  • Provides radiation monitor readings according to shielding and volatile material discharge.
  • Choice of makeup by diesel pump, firewater hose, spray, etc.
  • Simulates the outcome of deciding to promote air cooling to prevent a zirconium fire or to block air cooling to extinguish the fire.
  • Simulates the outcome of of protective action or evacuation.

© 2007 Micro-simulation Technology